A substrate, such as a carrier substrate, is often used to support a semiconductor device, such as a semiconductor wafer that includes a plurality of dies, to permit further processing on the semiconductor device. For example, a semiconductor device may include a plurality of structures, such as pads, pillars, vias, or the like, on a first or front side of the device. During the processing of the semiconductor device, the thickness of the semiconductor device may need to be reduced. Various processes, such as, but not limited to, chemical mechanical planarization, grinding, and/or dry etching, may be applied to the back, or second, side of the semiconductor device to remove material from the semiconductor device. For example, the thickness of the semiconductor device may be reduced from a first thickness, such as 775 microns, down to a second thickness, such as 70 microns, using various processes known by one of ordinary skill in the art. Furthermore, various processes, such as, metallization, photolithography patterning and electrical chemical plating, may be applied to the back, or second, side of the semiconductor device to form structures such as pads, pillars, or the like, for the semiconductor device.
Presently, a semiconductor device, such as a semiconductor wafer, may be temporarily bonded to a substrate, such as a carrier wafer, with a temporary adhesive to form a temporary semiconductor device assembly. For example, the first or front side of the semiconductor wafer may be bonded to a carrier wafer with a temporary adhesive that is spin coated onto the carrier wafer. After completing the processing on the second, or back, side of the semiconductor wafer, the semiconductor wafer is removed from the carrier wafer. Typically, the semiconductor wafer is removed, or debonded, from the carrier wafer by thermal/mechanical sliding. In other words, the temporary semiconductor device assembly is heated and force is applied to slide the semiconductor wafer off the carrier wafer. The present process of removing the semiconductor wafer from the carrier wafer may result in, among other things, die cracking and/or pillar smearing. Further, the present process may result in breakage of the semiconductor wafer itself. The edges of the semiconductor wafer may break, crack, or chip during the removal/debonding process.
A temporary adhesive having a relatively low glass transition temperature may be used to bond the carrier to the semiconductor device. The adhesive with the relatively low glass transition temperature is used to better enable that the carrier may be removed from the semiconductor device after the requisite processing. However, the semiconductor carrier and substrate assembly may be subjected to elevated temperatures during the processing potentially causing undesired movement between the carrier and semiconductor device.
A glass carrier may be used to support a semiconductor device during processing. After the requisite processing on the backside of the semiconductor device, a laser may be applied to the adhesive through the glass carrier to release the glass carrier from the semiconductor device. However, glass carriers typically have poor thermal transfer and high mismatch of coefficient and thermal expansion (CTE) which cause wafer warpage issues, and may also sag during processing of the semiconductor device due to the low elastic modulus.
A silicon (Si) carrier substrate having a high thermal conductivity, good rigidity, and a CTE match to a Si semiconductor device may have various advantages compared to a glass carrier used for semiconductor device backside processing. However, a Si carrier typically cannot be removed from the semiconductor device by applying a laser to the adhesive. Instead, a Si carrier may be removed by a thermal/mechanical process, which potentially may damage the semiconductor device, as discussed herein.
Additional drawbacks and disadvantages may exist.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the scope of the disclosure as defined by the appended claims.